Metra will clear the air in its train cars

Metra appears to have found a way to dramatically clean up the air inside its stainless-steel cars, but spikes of lung- and heart-damaging diesel pollution will remain a lingering problem on the platforms at Chicago's major rail stations.

In response to a Tribune investigation, the rail service is switching to more efficient air filters that testing shows can reduce the average amount of diesel soot inside its cars by 75 percent during outbound trips. The new filters are among several equipment changes studied during the past six months to curb exposure to noxious smoke from Metra's fleet of dirty, disco-era locomotives.

The results are promising enough that Metra plans to spend $200,000 a year — less than two-hundredths of 1 percent of its $1.04 billion budget — to equip all of its cars with high-efficiency filters that screen out diesel pollution. The filters will be installed in every car within 90 days.

"We care about our customers, and we're showing by our actions that we take seriously the concerns you brought to our attention," Alex Clifford, Metra's executive director, said in an interview.

Researchers estimate that more than half of people's daily exposure to diesel pollution comes during their commute. More than 245,000 commuters move through Chicago's three downtown stations every weekday.

Tiny soot particles, so small that thousands could fit on the period at the end of this sentence, can lodge deeply in the lungs and penetrate the bloodstream. Breathing in even small amounts can inflame the lungs and trigger asthma attacks; chronic exposure can cause cancer, heart attacks, brain damage and premature death.

Metra employee unions have raised concerns about diesel pollution for decades. But until now little was done in response.

"We've got complaints about the trains at Union Station going back to the early 1970s," said Paul Piekarski, a statewide official with the Brotherhood of Locomotive Engineers and Trainmen union. "It's time to fix this problem once and for all."

During the latest round of testing, Metra consultants determined that more efficient filters, classified as MERV 13 by an industry rating system, were the only fix that substantially reduced the amount of diesel soot breathed in by commuters. Metra also tested hoods over air intakes, shields that deflected exhaust to the sides of the engine and equipment that automatically shut down ventilation systems during stops.

Without the filters, soot levels averaged about 67 micrograms per cubic meter in the first car behind the locomotive, according to a Metra slide presentation. The average amount of pollution dropped to about 16 micrograms per cubic meter once the more efficient filters were in place.

The filters also smoothed out spikes of diesel pollution to about 24 micrograms per cubic meter, down from 92.

By contrast, typical soot levels in urban areas like Chicago range between 1 and 2 micrograms per cubic meter.

"Even if we bought a brand-new locomotive, it might not solve the problem without these more-efficient filters," Clifford said.

Metra is excited about the filters but acknowledged that they won't help reduce exposure for people waiting for trains downtown.

Metra's testing confirmed that high soot levels at Union Station, the Ogilvie Transportation Center and LaSalle Street Station lead to higher amounts inside passenger cars during trips away from the city. The problem is especially noticeable at Union Station, where trains are cramped inside tunnels below eight skyscrapers.

Under agreements with Amtrak, the national passenger rail service that owns Union Station, building owners are required to maintain ventilation ducts and fans that suck diesel exhaust out of the tunnels. But Amtrak and Metra officials said that at the Old Post Office, just south of the station, the fans frequently break down or fail to operate.

The shuttered building was purchased in 2009 by Bill Davies, a British developer. In an email response to questions, an engineering firm hired by Davies' International Property Developers said the ventilation system is checked regularly, and blamed the problem on idling trains and other property owners.

"The intention is that IPD and Union Station will work together to ensure an increasingly safe environment as the development progresses," the email concluded.

In a letter Tuesday to Joseph Boardman, Amtrak's president and chief executive officer, Sen. Dick Durbin called for a more aggressive response to the ventilation problems. "Stations without proper ventilation, filtration and air flow can keep toxic gases trapped inside stations used by thousands of people each day," Durbin wrote.

During a May inspection, Amtrak discovered that two of the Old Post Office's eight fans weren't operating. Another inspection has been scheduled for early next month, said Marc Magliari, an Amtrak spokesman.

As part of its air quality testing during the past six months, Metra used the same handheld device rented by the Tribune to measure black carbon, or soot, a key ingredient in diesel exhaust. Manufactured by Magee Scientific, of Berkeley, Calif., the equipment is similar to devices used in peer-reviewed studies.

Metra's testing showed the worst pollution problems are on trains leaving the south platform at Union Station. The testing also shows that exposure to the dirtiest air depends on where commuters sit. Soot levels generally are highest inside the first car behind the locomotive, drop in the second car and decline substantially in the last car.

Compared with inbound trains, levels are significantly higher during outbound trips, largely because diesel pollution from idling locomotives collects inside the open passenger cars before departure. Diesel exhaust also is sucked into the cars as locomotives pull outbound trains toward the suburbs.

Metra says it doesn't have enough money to replace its aging locomotives with cleaner models. Instead, it is refurbishing a third of its fleet to keep the 1970s-era engines running for at least another quarter-century without pollution controls found on newer models.

But in response to concerns raised by the Tribune investigation, the rail service already has switched to cleaner diesel fuel that has reduced soot emissions by about 8 percent. Metra also is seeking federal funding to install technology that automatically shuts down the engines if they idle for longer than 10 minutes, another change that can reduce the amount of acrid blue smoke hovering inside the downtown stations.

Commuters frequently complain about diesel exhaust. One emailed a video to the Tribune this week that shows a burst of locomotive pollution enveloping commuters as they walk past a train revving up to leave Union Station.

"I try to hold my breath for as long as I can," said Laura Zeitler, a consultant who commutes between Naperville and Union Station. "If you wait too long on the platform, you feel like you are choking on all of that nasty pollution."